1. Field of the Invention
The invention relates to a connection between a cutter holder and a tool carrier of an internal-turning head with a fine-adjustment mechanism, having a setscrew for releasably connecting the cutter holder to the tool carrier.
2. Description of the Related Art
A connection of this kind is known from Swiss Patent No. CH-A-641,706. In this case, the cutter holder is inserted into a recess in the tool carrier, which recess runs obliquely to the adjustment direction of the tool carrier and is fixed by a screw. Similar connections have been disclosed in the prior art by European Patent No. EP-A-0,478,239 and by German Patent No. DE-A-35 08 434. Moreover, an internal-turning head is known in which the tool carrier and the cutter holder are connected to one another by means of a serration as an anti-rotation safeguard. Moreover, an internal-turning head is known in which the tool carrier has an end face which runs obliquely to the adjustment direction of the tool carrier and against which the cutter holder, which is provided with a correspondingly oblique face, is pressed by means of a setscrew.
The abovementioned known internal-turning heads in each case have a main body in which the tool carrier is radially displaceable for the purpose of setting the diameter of the bore to be machined. The displacement is effected via an adjustment screw which is mounted in the main body and has a fine thread. The cutter holder, on which a cutting tip, for example a throw-away cutting tip made of sintered carbide, is releasably mounted, is arranged on the tool carrier. Worn cutters or a damaged cutter holder can easily be replaced. The practical requirements for the connection between the cutter holder and the tool carrier are that it should be reliable, as rigid as possible, secure against rotation and able to be positioned unambiguously. Moreover, the cutter holder should be simple to replace. The known connections satisfy these requirements only partially or unsatisfactorily. This is particularly true when considered in conjunction with the trend towards very hard and heat-resistant cutting materials leading to ever higher metal-removal rates. This trend is increasingly leading to higher cutting speeds. Since the internal-turning head forms the linking element between the cutter and the work spindle of a machine tool, the performance of the machine tool must be transmitted optimally to the cutter. The connection of the cutter holder to the tool carrier is decisive in achieving a satisfactory machining result.